Lens surface former and polishing tool

Abstract

A lens surface former and polishing tool of one-piece construction and made, for example, of aluminium, aluminium alloy or a zinc-based alloy with one side surface of the block being of convex form and the other side surface of the block being of concave form, in which, projecting radially from the cylindrical peripheral surface of the main part of the block, is an annular flange or ledge which is interrupted at equi-distant points by four tapered location grooves or slots extending longitudinally of the tool so as to be parallel to the longitudinal axis of the tool, the flange or ledge with its tapered grooves or slots thereby permitting the tool to be quickly mounted on holding means forming part of a lens-grinding or lens-generating machine.

I claim: 
     
       1. A lens surface former and polishing tool comprising a generally circular block of material formed symmetrically about a rotational axis of the tool, lens-generating or lens-forming surfaces on two opposite-facing sides of the block, at least one flange or ledge formed on the block and projecting radially outwards with respect to the rotational axis of the tool to act as securing means for securing the block on a lens-generating machine or a lens-polishing machine, and location grooves formed in the flange or ledge on the block, and wherein at least one of the grooves is of a different width from the other grooves so as to permit the grooves to cooperate with holding lugs of unequal width for axis location on a lens-polishing machine.   
     
     
       2. A lens surface former and polishing tool according to claim 1, wherein the location grooves extend longitudinally of the tool so as to be parallel to the rotational axis thereof. 
     
     
       3. A lens surface former and polishing tool according to claim 1, wherein the location grooves are of tapered form. 
     
     
       4. A lens surface former and polishing tool according to claim 1, having four location grooves, two or one width and the other two of a different width. 
     
     
       5. A lens surface former and polishing tool according to claim 1, wherein the radially-projecting flange or ledge is formed integrally with the block. 
     
     
       6. A lens surface former and polishing tool according to claim 1, wherein the block is made of aluminium, aluminium alloy or a zinc-based alloy. 
     
     
       7. A lens surface former and polishing tool according to claim 1, wherein the flange or ledge on the block has upper and lower surfaces which lie at right angles to the rotational axis of the tool. 
     
     
       8. A lens surface former and polishing tool according to claim 1, wherein one side surface of the block is convex while the other side surface is concave. 
     
     
       9. A tool/tool holder assembly comprising a lens surface former and polishing tool as claimed in claim 1 which is held on a tool holder, said holder being in the form of a cup-shaped part or nest which receives the lens tool in such a way that a cylindrical surface on the lens tool opposes a corresponding cylindrical surface on the cup-shaped part or nest, the cup-shaped part or nest also having spaced-apart lugs which engage in the grooves on the tool so as to drive the latter. 
     
     
       10. A tool/tool holder assembly comprising a lens surface former and polishing tool as claimed in claim 1 which is held on a tool holder, said holder being in the form of a disc having fingers which enter the grooves in the tool. 
     
     
       11. A tool/tool holder assembly comprising a lens surface former and polishing tool held on a tool holder, the lens surface former and polishing tool comprising a generally circular block of material formed symmetrically about a rotational axis of the tool, lens-generating or lens-forming surfaces on two opposite-facing sides of the block, at least one flange or ledge formed on the block and projecting radially outwards with respect to the rotational axis of the tool to act as securing means for securing the block on a lens-generating machine or a lens-polishing machine, and location grooves formed in the flange or ledge on the block, and   said tool holder being in the form of a cup-shaped part or nest which receives the lens tool in such a way that a cylindrical surface on the lens tool opposes a corresponding cylindrical surface on the cup-shaped part or nest, the cup-shaped part or nest also having spaced-apart lugs which engage in the grooves on the tool so as to drive the latter.   
     
     
       12. A tool/tool holder assembly according to claim 11, wherein the tool has four location grooves, two of one width and the other two of a different width, and wherein the tool holder has four lugs, two of one width and two of a different width, so as to match the four grooves on the tool.